Our radiators are constructed of materials that provide better heat dissipation than the factory units. Additionally, our radiators do not become weak or brittle due to constant temperature cycling. Glass reinforced nylon, as used by OE manufacturers, will eventually deteriorate resulting in a cracked or broken radiator neck. This failure has become more common due to the increased temperatures in the current generation of BMW engines. The normal operating temperature of a Double Vanos engine is around 110° C (230° F). Unfortunately, there is no way to tell what the real temperature is in the engine without special equipment. According to the BMW WDS, the instrument cluster temperature display will read normal between 75°-113° C (167°-235.4° F). Nylon just doesn't hold up under these conditions.